The Seattle P-I had a front-page article yesterday entitled Harmful pesticides found in everyday food products. Twenty one kids from our area aged 3 to 11 were given conventionally grown food to eat. Researchers found malathion and chlorpyrifos, two insecticides, in the kids' urine and saliva. Within a day and a half of switching to organic foods, the childrens' urine showed no signs of the pesticides.
What's so bad about malathion and chlorpyrifos? Chlorpyrifos is developed from nerve gas, is causing people to get sick in agricultural areas, and there have been lawsuits to get the EPA to ban it. Malathion also messes with the nervous system.
Read the article. Ask your farmers what they spray their crops with, or if you can't, go organic.